Modular battery control system architecture

ABSTRACT

Implementations of the present disclosure involve a battery management architecture for a battery system involving a plurality of connected power units. In general, the BMS comprises one or more management sub-controllers connected serially to a master controller associated with the powered device. Each of the one or more management sub-controllers may be associated with a power unit of the battery, with each power unit included one or more battery modules or battery cells. Each of the one or more management sub-controllers in the BMS share a communication link to provide and receive information and instructions associated with the battery system. In general, the BMS of the present disclosure provides flexibility and modularity to the architecture of battery systems for customization of the battery system for a variety of uses and environments.

RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application 61/551,770 filed on Oct. 26, 2011, the entirety of which is incorporated herein by reference.

TECHNICAL FIELD

Aspects of the present disclosure generally relate to a battery management system for a complex battery system. More particularly, aspects of the present disclosure relate to a modular battery system architecture and method for control of the same.

BACKGROUND

Larger and evermore complex battery systems are being developed to provide larger voltages, more power, and larger capacity for modern uses, such as in electric vehicles, hybrid vehicles, home power supplies, and power storage for alternative energy generation platforms such as wind and solar. Such systems sometimes include several battery units interconnected in some manner to provide the large voltage and power. For example, complex battery systems may include several lower voltage battery packs that, when combined in series, provide a higher voltage.

It is with these issues in mind, among others, that aspects of the present disclosure were conceived and developed.

SUMMARY

Aspects of the present disclosure involve a battery management system. The system includes a controller involving a processing device configured to transmit and receive one or more control signals for configuring a battery system, a downstream communication link, and an upstream communication link. The system further includes a first sub-controller connected to the downstream communication link and the upstream communication link of the controller. The first sub-controller is configured to receive one or more first power unit control signals from a controller on the downstream communication link and, in response to the one or more first power unit control signals received from the controller, configure a first plurality of battery cells in response. The system further includes a second sub-controller connected to the first sub-controller and configured to receive one or more second power unit control signals from the first sub-controller and, in response to the one or more second power unit control signals received from the first sub-controller, configure a second plurality of battery cells.

Aspects of the present disclosure further involve a method for controlling a battery system comprising a plurality of power units. The method includes the operation of receiving a first control signal from a controller on a first downstream communication link at a first management control sub-controller associated with a first power unit of the battery system where the first management control sub-controller is connected to the controller by the first downstream communication link. The method further includes the operation of configuring at least one setting of the first power unit in response to the received first control signal and receiving at least one performance indicator from the first power unit. Additionally, the method includes the operation of storing the at least one performance indicator of the first power unit in a computer-readable storage device associated with the first management control sub-controller. Finally, the method involves the operation of transmitting a second control signal on a second downstream communication link to a second management control sub-controller associated with a second power unit of the battery where the second control signal is substantially similar to the first control signal.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a complex battery system architecture, including a battery management system providing modularity to the battery system.

FIG. 2 is a block diagram illustrating the communication and power links between the components of the battery management system of FIG. 1.

FIG. 3 is diagram illustrating an exemplary communication flow between the components of the battery management system of FIG. 1.

FIG. 4 is a block diagram illustrating a controller of a battery management system for the complex battery system of FIG. 1.

FIG. 5 is a block diagram illustrating a battery management system sub-controller for a complex battery system of FIG. 1 including electrical isolation on inputs to the sub-controller.

DETAILED DESCRIPTION

Aspects of the present disclosure involve a battery management architecture for a battery system involving a plurality of connected power units, with each power unit associated with one or more battery cells. The battery management system (BMS) provides modularity within the battery system for ease of expansion and cell replacement, among other advantages. Further, the BMS also provides the battery system independence from cell or pack voltages, charge and discharge currents, system capacity or battery chemistry. In general, the BMS comprises one or more management sub-controllers connected to a master controller. Each of the one or more management sub-controllers may be associated with a power unit of the overall battery, with each power unit including one or more battery modules or battery cells. Each of the one or more management sub-controllers in the BMS share a communication link to provide and receive information and instructions associated with the complex battery system. In one embodiment, the shared information and instructions may facilitate charging, charge balancing, load balancing, discharge, cell replacement, module replacement, pack replacement and other functions to ensure proper battery function and longevity. In general, the BMS of the present disclosure provides flexibility and modularity for customization of the complex battery system for a variety of uses and environments.

FIG. 1 is a block diagram illustrating one embodiment of a battery system architecture 100, including a battery management system providing modularity to the battery system. The battery system 100 shown may be used in any environment or device where a large voltage, stored electricity or power is needed. For example, the battery system shown may be utilized in a hybrid vehicle, or an electric vehicle, or as a power supply for a residence. In another example, the battery system may be used to provide back-up power for one or more devices in data center.

The battery system 100 of FIG. 1 includes a controller 102 electrically connected to one of the one or more power units 104-108. In one embodiment, the controller 102 may be included as part of the battery system 100 for interfacing with the device or devices to be powered by the battery system or to otherwise receive or deliver electrical energy from the battery. In another embodiment, the controller 102 is integrated into the powered device or some other external component. For example, the controller 102 may be a main controller of a hybrid car such that the power units 102-108 may be connected to the existing controller 102 upon installation of the battery in the hybrid car, and the battery provides motive energy to the electric motor on demand and receives energy during regenerative braking and charging. The battery may also receive or deliver energy in vehicle-to-grid applications or other similar applications.

Regardless of whether the controller 102 is included as part of the battery or connected to the controller upon installation in the powered device, the controller may provide the general instructions and control signals for managing the various modules and components of the battery system. Further, the controller 102 may also receive signals from the components of the battery system for utilization during operation of the battery system, such as information about the performance of the modules or components of the battery system. For example, the controller 102 may provide signals to the one or more power units 104-108 to power-down or power-up in response to a need with the powered device. The controller 102 may also receive information about the power units 104-108, such as state of charge, voltage and/or current of each unit, the temperature of each unit and verification of proper operation of the modules and cells associated with the power units. In another example, the controller 102 may provide request signals to the power units 104-108 for balancing of the power units, as explained in more detail below. The controller 102 or other components of the BMS 100 may also store historical battery information. A more detailed description of the components of the controller 102 and the communication between the controller and the power units 104-108 is provided below.

As mentioned, the controller 102 may be in electrical communication with one of the one or more power units 104-108. As shown in FIG. 1, the controller 102 is connected to a first power unit of a plurality of serially connected power units, designated in FIG. 1 as power unit 1 (104). More particularly, the controller 102 is electrically connected to a battery management system (BMS) sub-controller 110 of the first power unit 104. As explained in more detail below with reference to FIG. 2, the controller 102 may be connected to the BMS sub-controller 110 of the first power unit 104 through any known means for wired communications, such as over metal wires or optical fibers. In general, the connection between the controller 102 and the power units 104-108 of the battery system need only be sufficient to transmit control signals to and from the control unit. Further, in some embodiments, the controller may connect to BMS sub-controller 1 (110) to provide power signals to power unit 1 (104). In one specific implementation, communication and power occurs over a wiring harness of four wires between units. The components of the BMS sub-controller are discussed in more detail below with reference to FIG. 5.

As also shown in FIG. 1, the power unit 104 may include a BMS sub-controller 110 electrically connected to one or more battery modules 112-116. In one embodiment, the battery modules 112-116 are connected in series to the BMS sub-controller 110. Thus, in power unit 1 (104), battery module 1 (112) is connected to the BMS sub-controller 1 110, battery module 2 (114) is connected to battery module 1 (112) and so on to battery module X (116), designated as such to illustrate that any number of battery modules may be connected in the serial connection. In this manner, each power unit 104-108 may include any number of battery modules as needed to provide the desired voltage and power for the particular power unit. Further still, each battery module within each power unit 104-108 may include any number of cells. For example, battery modules 1 (112)-X (116) of power unit 1 (104) may each include six battery cells (not shown), although other cell numbers are possible. Thus, although shown in FIG. 1 as a single module, each module of the battery system may include any number of batteries or cells.

In addition, the cells of any battery module of the battery system may be of varying chemistry makeup such that the battery system 100 may include a variety of different types of batteries. For example, module 1 (112) of power unit 1 (104) may include a first chemical type of battery while module 1 (114) of power unit 2 (106) may include a second chemical type of battery. For example, the cells may include any combination of lithium ion, sodium sulfur, lithium-sulfur, nickel-cadmium, nickel metal hydride, lead acid and any other conventional or to be developed cell type. Thus, through this modular nature of the power units, each power unit 104-108 of the battery system 100 may include any type of battery chemistry that provides the desired amount of voltage and power for that particular power unit.

In other embodiments of the power unit 104, the battery modules 112-116 may be connected in other configurations beside serially. For example, the modules 112-116 may be connected in a parallel connection. In another example, several battery modules may be connected in serial, which are then connected in parallel with other serially connected modules. In general, the battery modules 112-116 of any power unit 104-108 may be connected in any manner to provide the power unit with the desired voltage, power, current charge or discharge capacity and/or storage capacity, or other characteristics.

As mentioned above, the battery system 100 may include a plurality of power units 104-106 connected serially to the controller 102. As shown in FIG. 1, a second power unit, power unit 2 (106), is connected to the first power unit 104 in a similar manner to the connection between the controller 102 and the first power unit 104. More particularly, the BMS sub-controller 118 of power unit 2 (106) is in electrical communication with the BMS sub-controller 110 of power unit 1 (104). Similar to that of power unit 1 (104), the BMS sub-controller 118 of power unit 2 (106) connects to power unit 1 in such a manner as to receive control signals and other communications from power unit 1 and to provide status and other information about power unit 2 to power unit 1. This communication may occur through any known means for communicating electrically, including wired or optical fibers. A power connection may also be present between power unit 1 (104) and power unit 2 (106). In general, the connection between power unit 1 (104) and power unit 2 (106) of the battery system need only be sufficient to transmit some control signals between the power units. In one particular arrangement, the controller 102 and BMS sub-controllers 110, 118, 126 are connected in a serial daisy chain.

In this manner, any number of power units 104-108 may be connected in the battery system 100. This is illustrated in FIG. 1 as the connection of power unit X (108) in the serial chain of the connected power units. Power unit X (108) represents the last power unit in the serial chain of power units of the any number of connected units. Thus, the battery system 100 shown in FIG. 1 is expandable or customizable to include any number of such units as needed for the system. Also, although depicted as similar in construction to power unit 1 (104), the power units 106-108 of the battery system 100 may be constructed in different configurations as the other power units. For example, power unit 2 (106) may include fewer or more battery modules 120-124 than power unit 1 (104). Also, the battery modules 120-124 of power unit 2 (106) may include a different number and type of cells. Further still, the battery modules 120-124 of power unit 2 (106) may be connected in a different manner than those of the other power units 104, 108 of the battery system 100, such as in a parallel manner. Thus, through the use of the battery management system discussed herein, the battery system 100 is customizable in the number of power units 104-108 included in the system, as well as the number of battery modules, battery types included in each battery module and the configuration of battery modules for each power unit.

In one aspect, the BMS provides for the removal, replacement, addition and/or exchange of power units with minimal disruption to the system overall. For example, if power unit 2 (106) of the battery system 100 fails or falls below some performance criteria, the power unit may be removed and replaced with a replacement unit that operates properly and within specifications without the need to customize or reprogram the controller 102. Further, as explained in more detail below, it is not required that the added or replacement units 104-108 have the same structure or characteristics of the other power units. Rather, the power units 104-108 may be added or exchanged in near real time once the new units are connected in the communication chain of the battery system 100. The integration of the power units 104-108 in the communication chain of the system 100 is described in more detail below. The capability to insert or replace power units 104-108 within the battery system 100 is markedly different from previous battery systems.

FIG. 2 is a block diagram illustrating a portion of the communication and power links between the BMS sub-controllers and controller of the battery management system of FIG. 1. Thus, the controller 202 and BMS sub-controllers 210-226 of FIG. 2 are similar to the related components shown in FIG. 1 as discussed above. It should be noted that similar components are numbered similarly between the Figures. For example, the controller has a notation of 102 in FIGS. 1 and 202 in FIG. 2 to indicate that these components are similar. In addition, although not shown in FIG. 2, the BMS sub-controllers 210-226 of FIG. 2 may be connected to and transmit and receive information from one or more battery modules connected to the sub-controllers, as shown in FIG. 1.

As shown in FIG. 2, the controller 202 may transmit control or other signals to the BMS sub-controllers 210-226 to control the BMS sub-controllers and the associated battery modules. Although the term “control signal” is used herein, the term should be construed to include any type of signal that includes information between the components of the battery system, such as instructions to be executed or information about the operation of the various components of the system. In general, the control signals from the controller 202 propagate through the serial connection of the BMS sub-controllers 210-226 on a communication link referred to herein as the “downstream link”. More particularly, the controller 202 may provide the control signal on the downstream link 240 between the controller 202 and BMS 1 (210), or the first BMS sub-controller in the serial connection. The BMS sub-controller 1 210, upon receipt of the control signal from the controller 202, may respond to the control signal by transmitting a response to the controller on an upstream link 250 between the controller and BMS 1. In addition to the response or in the alternative, BMS 1 (210) may transmit the control signal on the downstream link 242 between BMS 1 and BMS sub-controller 2 218. In some embodiments, however, BMS 1 (210) may interpret the control signal as being associated with BMS 1 only and will not transmit the control signal to BMS 2 (218). For example, the control signal may include a header or other portion that includes an address for a particular BMS of the system such that, when received by the particular BMS, is recognized as being associated with the particular BMS only. In other embodiments, BMS 1 (210) may generate a new control signal in response to the control signal received by the controller 202 and transmit the newly generated control signal on downstream link 242 to BMS 2 (218). The general formatting of the control signals transmitted on the upstream and downstream links is discussed in more detail below with reference to FIG. 3.

In response to receiving the control signal from BMS 1 (210), BMS 2 (218) may respond in a similar manner by transmitting a response signal on upstream link 248 to BMS 1, which in turn may respond to the response signal provided by BMS 2 and/or transmit the signal to the controller 202 on upstream link 250. In another example, BMS 1 (210) may, in response to the signal received by BMS 2 (218), generate a control signal to transmit to BMS 2 on downstream link 242 or to the controller 202 on upstream link 250. In general and as discussed in more detail below with reference to FIG. 3, the BMS sub-controllers 210-226 may respond to any received control signal, whether received upstream or downstream, by transmitting the control signal on any available communication link, configuring the BMS in some manner in response to the control signal, by generating a subsequent control signal and/or transmitting the subsequent control signal on any available communication link. In addition, the BMS sub-controllers 210-226 may also generate and transmit a control signal at any time in response to states internal to the BMS sub-controller or associated battery modules.

This process of receiving and transmitting the control signals to/from the controller 202 and BMS sub-controllers 210-218 may continue along the serial connection of BMS sub-controllers to BMS sub-controller X (226), which represents the last BMS sub-controller in the serial chain of any number of BMS sub-controllers. BMS sub-controller X (226) communicates with the rest of the BMS sub-controller chain on downstream link 244 and upstream link 246 in a similar manner as described above.

The communication links between the controller and the BMS sub-controllers, as well as between the BMS sub-controllers may be any type of electrical communication known or hereafter developed to communicate signals through a physical medium between electrical devices. Thus, the communication between the components may occur over wires or optical cabling. In addition, the communication may occur based on a common clock signal to the components or may occur asynchronously.

In addition to the communication links, the controller 202 may also provide a power enable signal and/or electrical power to the BMS chain on power link 252. As described in more detail below, the power enable signal provided by the controller 202 aids the battery system in saving power and operating needs. Further, in a manner similar to the control signals being propagated along the serial chain of BMS sub-controllers 210-226, the power enable signal may also be propagated from sub-controller to sub-controller along power links between the sub-controllers, illustrated in FIG. 2 as power link 254 between BMS 1 (210) and BMS 2 (218) and power link 256 between BMS 2 and BMS X (226).

As mentioned above, each of the one or more BMS sub-controllers may provide and receive information and/or instructions associated with the battery system. For example, the BMS sub-controller for any one power unit may acquire the voltages and/or temperature of the battery modules associated with the BMS sub-controller. This information may then be provided to the controller or other BMS sub-controllers. In another example, the controller may provide an instruction to the BMS sub-controllers of the battery system to perform load balancing among the battery modules.

FIG. 3 is diagram illustrating an exemplary communication flow between the components of the battery management system of FIG. 1. The communication flow illustrated is but one example of the process by which the controller and BMS sub-controllers may communicate and is provide here to further illustrate the communication possibilities of the battery management system disclosed. However, the battery management system may employ any known or hereafter developed communication protocol to share information and instructions between the controller and the one or more BMS sub-controllers. Additionally, the communication example of FIG. 3 is described below in relation to the battery management configuration similar to those shown in FIG. 1 and FIG. 2. In particular, the communication protocol example is shown for a battery system including a controller and three BMS sub-controllers connected in a serial chain. It should be appreciated, however, that other configurations, such as configurations with more than three BMS sub-controllers or sub-controllers connected in a non-serial manner, may result in a different communication protocol than that provided in example of FIG. 3.

In the example communication provided in FIG. 3, a message is generated by the controller 202 that requests information from each of the three BMS sub-controllers associated with the controller. This is designated in the graph as box “MSG 1” in the lower left corner of the graph. More particularly, as the MSG 1 box is included above the controller notation 301 indicating that the controller generates or receives MSG 1. Additionally, the x-axis of the graph indicates that MSG 1 begins this particular communication at time 0. It should be appreciated that the time values provided in FIG. 3 are merely place holders to indicate a later time and do not correlate to actual time values, which may depend on any number of factors, including processing time of the controller and BMS sub-controllers, transmission speeds of the upstream and downstream links and the presence or absence of a system control clock. Further, although in this example MSG 1 is a command or instruction generated by the controller 202 that requests information from the BMS sub-controllers 210-226, the message may be any communication or instruction to the BMS sub-controllers. For example, MSG 1 may be an initialization command to initialize the BMS sub-controllers with the controller. This initialization command is explained in more detail below. In another example, MSG 1 may instruct the BMS sub-controllers 210-226 to begin a load balancing routine to balance the battery system. In addition, the message may originate from some other component within the system or separate from the system besides the controller.

At time 1, the controller 202 transmits MSG 1 to BMS 1 (210) over downstream link 240. This is indicated in FIG. 3 as transmission 302 as MSG 1 appears in BMS 1 column 303. As indicated above, MSG 1 may instruct BMS 1 to return information, such as voltage or temperature readings of the battery modules associated with the BMS sub-controller, back to the controller 202. This information may be gathered and stored by BMS 1 (210) during normal operation of the sub-controller and related power unit. Thus, in response to MSG 1, BMS 1 (210) transmits the stored information, shown as box RSP 1 at time 2, to the controller 202 on upstream link 250 (shown in graph as transmission 304). Also, BMS 1 (210) may also retransmit MSG 1 to the next BMS sub-controller in the serial chain. For example, BMS 1 (210) transmits MSG 1 to BMS 2 (218) over downstream link 242 (shown in graph as transmission 306).

In response to receiving the requested information (RSP 1) from BMS 1 (210), the controller 202 may then generate a “NEXT” command at time 3 and transmit 308 the NEXT command to BMS 1 (210) over downstream link 240 to propagate the NEXT command along the serial chain. In general, the “NEXT” command instructs the BMS sub-controller that receives the command to transmit upstream any information being held by the sub-controller. For example, BMS 2 (218), in response to receiving MSG 1 transmits at time 3 the requested information, shown as box RSP 2, along upstream link 248 to BMS 1 (transmission 310). Upon receipt of this information, BMS 1 (210) may store RSP 2 until a command from the controller 202 is received on how to process the information. This command is the NEXT command transmitted 308 at time 3 by the controller 202 and received at time 4. Thus, upon receipt of the NEXT command, BMS 1 (210) transmits, at time 5, RSP 2 to controller 202 on upstream link 250, as shown in transmission 312. In this manner, the BMS sub-controllers may store any response or information received on the upstream link until a command (such as the NEXT command) is provided by the controller to continue propagating the response upstream to the next BMS sub-controller in the serial chain.

As illustrated, the NEXT command allows for the upstream propagation of information through the daisy chain configuration of the battery system to the controller. However, in some embodiments of the battery system, the controller 202 may be connected directly to each BMS sub-controller 210-226 such that the information provided by the sub-controllers may be transmitted directly to the controller. In this configuration, the NEXT command may be omitted as the information is sent directly to the controller. However, connecting the sub-controllers 210-226 to the controller 202 serially greatly reduces the physical wiring needed for communication between the controller and the power units.

Returning to time 2, BMS 2 (218) may, in addition to providing RSP 2 to BMS 1, transmit MSG 1 on the downstream link 244 to BMS 3 (transmission 314). In this manner, MSG 1 is propagated to each BMS sub-controller in the serial chain. In response to MSG 1, BMS 3 306 transmits the sub-controller information (RSP 3) on the upstream link 246 to BMS 2 (218) at time 4 (transmission 316). Also at time 4, BMS 1 (210) transmits the NEXT command to BMS 2 (218) over the downstream link 242 (transmission 318). As BMS 2 (218) is storing RSP 3 when the NEXT command is received, BMS 2 transmits RSP 3 over upstream link 248 to BMS 1 (transmission 320). BMS 2 (218) may also transmit the NEXT command to BMS 3 306 (transmission 322). However, because BMS 3 is the final BMS in the serial chain, BMS 3 is not storing any information from a down chain BMS and ignores the NEXT command.

Also at time 6, the controller 202 generates a second NEXT command in response to receiving RSP 2, or the information from BMS 2. The second NEXT command is then transmitted (324) to BMS 1 (210) in a similar manner as described above. Further, because BMS 1 (210) is storing RSP 3 (received at time 6), BMS 1 responds to the received NEXT command by transmitting (326) RSP 3 upstream to the controller. Also, the second NEXT command may be propagated through the serial chain through transmissions 328 and 330. However, because BMS 2 and BMS 3 do not store any additional information from downstream BMS sub-controllers, the NEXT command may be ignored by BMS 2 and BMS 3. As shown by the communication protocol outlined above and in FIG. 3, the controller 202 generates a message to retrieve information from the BMS sub-controllers of the battery system and receives response 1 through 3 that contain the information. In response to receiving the requested information, the controller 202 may then generate a second message, such as MSG 2 shown at time 9, which is then communicated to the BMS sub-controllers in a similar manner as described.

It should be noted that the transmission protocols described herein do not need to occur at regular timed intervals, but may also be asynchronous. Thus, the time indications included in FIG. 3 may indicate occurrences at a later time triggered by a received command or instruction. In other embodiments, the transmission of the signals may be governed by a clock signal common to the components of the battery system.

Another example of an instruction transmitted by the controller 202 in the manner described above is an initialization command (INIT) that may be used to address the BMS sub-controllers of the battery system. In general, the INIT command provides each BMS sub-controller in the battery system an address or ID number that corresponds to the sub-controller's relative placement in the serial chain of power units. Similar to the communication described above, the INIT command may be provided by a controller and an acknowledgment message may be provide back to the controller from the BMS sub-controllers.

In particular, the controller 202 of the battery system may transmit the INIT command downstream to BMS 1 (210). The INIT command includes an indication of the ID number of the first BMS that receives the INIT command, typically a value of “1”. Upon receipt, BMS 1 (210) will set an internal address register to the value contained in the INIT command and transmit an acknowledgement (ACK) message back to the controller 202 on the upstream link. In addition, BMS 1 (210) generates an INIT command that includes an ID number one greater than the stored ID number, in this case a value of “2”. Once generated, the newly generated INIT command is transmitted to BMS 2 (218) on the downstream link.

BMS 2 (218) processes the INIT command in a similar manner as BMS 1 (210) described above. Thus, BMS 2 (218) sets an internal address register to the value contained in the INIT command (“2”) and transmits an acknowledgement (ACK) message on the upstream link to BMS 1 202. In addition, BMS 2 (218) generates a INIT command that includes an ID number one greater than the stored ID number, in this case a value of “3”, and transmits the newly generated INIT command on the downstream link to the next BMS sub-controller in the serial chain. This action continues until each BMS sub-controller has received an INIT command and has an associated address or ID number.

In some cases, the INIT command may not be properly executed by the BMS sub-controller. For example, the INIT command may be corrupted during transmission such that the BMS sub-controller cannot recognize or verify an address or ID number. In another example, the BMS sub-controller may be the final sub-controller in the serial chain and, thus, cannot transmit a generated INIT command to the next BMS. In these cases, the BMS sub-controller may transmit a non-acknowledgment (NACK) signal on the upstream link to indicate that a failure has occurred in the addressing or initialization command.

Utilizing the NEXT commands as described above, the controller 202 can propagate each ACK or NACK responses upstream through the serial chain back to the controller. In general, the controller 202 continues to generate NEXT commands until a NACK message is received, indicating that each BMS sub-controller has been properly addressed within the serial chain. Thus, through the INIT command, the controller 202 can address each power unit connected in the battery system, regardless of the configuration of the power units within the system. By addressing the sub-controllers, the controller 202 may transmit messages directly to one or more sub-controllers of the system by including the address for the particular sub-controller in a header or other portion the message.

The functionality of the battery management system to initialize or address the connected power units associated with the controller provides flexibility in designing and configuring a battery system. For example, the battery management system described herein may be incorporated or utilized for different configurations and types of battery systems. Thus, a computing device using a 300 volt battery pack may utilize the battery management system in a similar manner as a computing device using a 240 volt battery pack, without the need to design a customized control system for the different computing devices. Rather, the proper power units for the computing device may be connected to the controller and, through the initialization and addressing operation described above, the controller may begin communicating with the power units, without the need for designing a customized controller and/or sub-controllers. In this manner, the battery management system described herein may be incorporated into varying battery pack configurations as needed by the powered computing device without minimal customizing to the components, providing a modular solution for battery pack management.

In addition, the battery management system described herein allows for any number of power units and battery management sub-controllers to be associated with the controller without the need for programming or configuring the controller as to the number of units connected. Rather, any number of power units may be connected serially in the battery system and the controller, through the initialization process described above, provides an address or ID number to the units without any prior knowledge of the number of units connected. Further, the initialization process informs the controller to the number of power units connected to the controller for future use by the controller in providing commands and information requests.

In addition, the battery system allows for the battery pack configuration to be altered with minimal configuring of the system. For example, a user of the battery system may remove power units or add power units to the battery system that may be recognized automatically by the system. For example, once the controller detects that a power unit has been removed or added (generally through receiving a command from an un-addressed unit or receiving a NACK response), the controller may begin the initialization process to remap the power units connected in the battery system. Depending on the transmission and processing speed of the system, this initialization process may be conducted in less than a second, allowing for the alteration to the configuration of the battery system quickly. In response, the controller may adjust the configuration of the entire battery system to account for the added or removed power unit (such as requesting more voltage from the remaining power units or distributing the requested power between the communicating power units) to provide the expected voltage from the battery system to the computing device.

In one embodiment, the battery management system may perform this initialization sequence at set intervals to ensure that the current battery system configuration is detected. In yet another example, the initialization process allows for the replacement of one or more power units without the need to address the units within the battery system as the controller, through the initialization process, provides the address to the unit or units regardless of where in the serial chain the replaced units are placed. In this manner, the initialization sequence of the battery systems described herein provides flexibility in the alteration and configuration of the battery system.

Once initialized, the controller may request information from the power units of the battery system for operation, charge, discharge and maintenance of the system. For example, each BMS sub-controller may store information concerning the battery modules associated with the sub-controller, such as the number of battery modules supported, voltage limits, estimated state of charge, module state of health, etc. This information may be requested from each BMS sub-controller by the controller for use in operation of the battery system. Further, as explained above, each power unit may include any number and kind of battery modules such that the power units may be of different configurations. Information for each power unit may be stored by the controller and used during operation of the battery system, such as for determining error conditions and/or operating parameters of the battery system.

In addition, the connection of the BMS sub-controllers to the controller to control the various power units of the battery system may be independent of the battery connection configuration. For example, some battery systems connect the power units in parallel rather than a serial connection for various performance considerations. However, it is not required that the BMS sub-controllers as described herein also be connected in a parallel manner. Rather, the controller and BMS sub-controllers may be connected serially and operate as described above, regardless of the configuration of the connection between the battery modules of the system. While the controller may be programmed to account for the parallel nature of the battery system, the communication links between the controller and the BMS sub-controllers, as well as between the BMS sub-controller themselves, may be done in a serial configuration such that the performance and communication of the controller and the BMS sub-controllers operates as described above. Thus, the battery management system may be independent of the battery pack structure.

Another advantage offered by the battery management system described herein is the capability to actively control the power supplied to each BMS sub-controller controller, to disable power to the BMS sub-controllers when the system is in an idle state or a fault state in response to a detected problem within the battery system. Further, by electrically isolating each BMS sub-controller, the sub-controllers are capable of communicating across large potential differences of the power units of the battery system. FIG. 4 and FIG. 5 show a simplified version of the components of the controller and BMS sub-controllers to illustrate this control of the power to the sub-controllers by the controller.

FIG. 4 is a block diagram illustrating a controller of a battery management system for the battery systems described herein. The controller 400 is similar to the controller shown in FIGS. 1 and 2 for communication with and control of a battery system. More particularly, the controller 400 communicates with one or more BMS sub-controllers of a battery system to control the battery modules associated with the BMS sub-controllers, including receiving information concerning the battery modules and for performing load balancing of the battery modules.

The controller 400 of the battery system includes a processor 402 or processing device connected to a storage device 404. The storage device 402, referred to as main memory 816, or a random access memory (RAM) or other computer-readable devices coupled to the processor 402 for storing information and instructions to be executed by the processor. Common forms of machine-readable medium may include, but is not limited to, magnetic storage medium (e.g., floppy diskette); optical storage medium (e.g., CD-ROM); magneto-optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM and EEPROM); flash memory; or other types of medium suitable for storing electronic instructions.

The storage device 402 also may be used for storing temporary variables or other intermediate information during execution of instructions by the processor 402. The controller may also include a read only memory (ROM) (not shown) and/or other static storage device coupled to the processor 402 for storing static information and instructions for the processor. The controller set forth in FIG. 4 is but one possible example of a controller that may employ or be configured in accordance with aspects of the present disclosure.

According to one embodiment, the processor 402 may execute one or more sequences of one or more instructions contained in the storage device 404. These instructions may be read into the storage device 404 from another machine-readable medium. Execution of the sequences of instructions contained in storage device 404 may cause processor 402 to perform one or more of the process steps described herein. In alternative embodiments, circuitry may be used in place of or in combination with the software instructions. Thus, embodiments of the present disclosure may include both hardware and software components.

As shown in both FIG. 4 and FIG. 2, the controller 400 may include a downstream link 440 for transmitting signals to other components of the battery system. Similarly, the controller 400 may include an upstream link 450 for receiving signals and other information from the battery system. The downstream link 440 and upstream link 450 may each be connected to a buffer 416 connected between the links and the processor 402 of the controller. These links provide the transmission media on which the control signals described above may be sent to the BMS sub-controllers of the battery system. As described, in some embodiments, the links may be wires or optical cabling communication links.

In addition, the controller may include a power supply 406 for providing power to the BMS sub-controllers of the battery system. More particularly, the power supply 406 may provide a power connection 452 and a common or ground connection to the BMS sub-controller connected to the controller. In one embodiment, the power for each BMS sub-controller connected to the controller 400 may be provided by the controller power supply 406. However, in other embodiments and explained in more detail below, the power for each BMS sub-controller is provided by the one or more battery modules associated with the sub-controller. In these embodiments, the power signal 452 provided by the controller 406 is a “power enable” signal that signals the BMS sub-controller to power the sub-controller from the associated battery modules. Thus, a high signal on the power line 452 enables power to the sub-controller, while a low signal on the power line removes power from the BMS sub-controller.

To control the power line 452, an enable switch 408 may be connected to the processor 402 of the controller 400. The enable switch 408 may be a physical switch, an electrical circuit equivalent or an instruction provided by the processor for enabling the power line 452. In general, the enable switch 408 is configured to receive a signal from the processor 402 that allows the signal on the power line 452 or disconnects the power line from the power supply 406.

FIG. 5 is a block diagram illustrating a BMS sub-controller for a battery system described herein, including electrical isolation on inputs to the sub-controller. In general, the BMS sub-controller 500 is similar to the BMS sub-controllers shown in FIGS. 1 and 2. Further, the BMS sub-controller 500 includes a processor 502 and storage device 504 in a similar configuration of the controller described above. Also similar to the controller described above, the BMS sub-controller 500 may include a downstream output link 542 for transmitting signals to other BMS sub-controllers of the battery system and an upstream input link 548 for receiving signals and other information from the other BMS sub-controllers. The downstream output link 542 and upstream input link 548 may each be connected to a buffer 516 connected between the links and the processor 502 of the controller. These links provide the transmission media on which the control signals described above may be transmitted to the BMS sub-controllers of the battery system. As described, in some embodiments, the links may be wires or optical cabling communication links.

As also shown, the BMS sub-controller 500 may receive a downstream input link 540 from either the controller or another BMS sub-controller for receiving control signals. In one embodiment, the downstream input link 540 may be connected to an electrical isolator 520, such as an opto-isolator designed to transfer electrical signals by utilizing light waves. In general, the electrical isolator 520 may be any known or hereafter developed isolating device for electrically isolating the power units. Similarly, the BMS sub-controller 500 may also include an upstream output link 550 from either the controller or another BMS sub-controller for transmitting control signals. In one embodiment, the upstream output link 550 may be connected to an electrical isolator 522 for isolating the upstream link from a connected BMS sub-controller or controller. These upstream and downstream links may be utilized by the BMS sub-controller to transmit and receive control signals as described above.

In addition, the BMS sub-controller 500 may include a power supply enable device 506 for enabling power to the BMS sub-controller. More particularly, the power supply enable device 506 may receive an enable signal on a power enable input 552. For example, the power enable input 552 may be connected to a controller of the battery system. The controller, similar to that described above with reference to FIG. 4, may provide a signal on the power enable input 552 line to enable power to the BMS sub-controller 500. When the enable signal is received, the power supply enable device 506 may begin supplying power to the BMS sub-controller 500, such as from the battery modules associated with the BMS sub-controller 500. In addition, the power enable input 552 may be connected to a electrical isolating device 524 to electrically isolate the BMS sub-controller 500 from the device supplying the power enable signal.

Further, the power supply enable device 506 of the BMS sub-controller 500 may also provide or retransmit the received power enable signal. More particularly, a power enable signal output 554 and common output 556 may be connected to the power supply enable device 506. The power supply enable device 506 may be configured to transmit a power enable signal on the enable signal output 554 under certain conditions. For example, the power supply enable device 506 may provide the enable signal on the power output 554 when the enable signal is received at the power enable input 552. In another example, the processor may control the power supply enable device 506 to provide the enable signal when a command from the controller is received or when certain conditions of the power unit are achieved.

As shown in FIG. 2, the BMS sub-controllers may be connected in a serial connection. Thus, turning to FIG. 5, the downstream output link 542 of the BMS sub-controller shown may be connected to a downstream input link of a similar BMS sub-controller and the input upstream link 548 may be connected to an upstream output link of the similar BMS. In this manner, the BMS sub-controllers may propagate signals or otherwise communicate on the upstream and downstream links. Further, the power output 554 may be connected to the power input of the similar BMS sub-controller for control of the power to the similar BMS sub-controller. Also, by utilizing the isolation devices 52-524, the BMS sub-controllers may be electrically isolated from each other to prevent damage to any one sub-controller should a failure occur at a connected sub-controller.

Utilizing the above described configurations and techniques for the battery system, the controller may also transmit one or more commands to the BMS sub-controllers to balance the cells and/or modules of the battery to protect the battery system and achieve greater performance. For example, battery systems composed of one or many cells may only supply enough current as the weakest module. In addition, battery systems may be damaged or become dangerous when the battery cells are over-discharged or over-charged passed the specifications of the battery cells. Further, a full charge and discharge of the battery cells provide a longer battery cell life cycle. To address this, the battery management systems described herein may balance the battery modules so they remain as close to equal as possible to provide the best performance.

To perform the cell balancing, the battery system may utilize the structures and methods described above. For example, returning to FIG. 1, the controller 102 may begin a cell balancing routine to balance the cells/modules of the battery system. The controller 102 may provide an instruction to the power units 104-108 connected to the controller instructing the power units to perform the balancing routine. More particularly, the controller 102 may transmit the instruction to BMS 1 110 of the first power unit in a similar manner as described above with reference to FIG. 3. In turn, BMS 1 110 may transmit or propagate the balancing instruction to BMS 2 118, and so forth down the serial connection of power units. An acknowledgement message may be transmitted from each BMS sub-controller back to the controller 102 to acknowledge receipt of the balancing command. In addition, the balancing command may include the target state of charge for each module or cell within the battery system. Upon receipt of the balancing command, the BMS sub-controllers may perform the balancing routine as described above for the modules and cells associated with that sub-controller by activating energy dissipating devices for those cells above the target state of charge. For example, the BMS sub-controller may provide a signal to close a switch to connect a resistor across the cell for a particular amount of time to remove energy from the cell.

In another embodiment, the controller 102 may request performance information from each BMS sub-controller connected to the controller. This information may contain performance statistics for the modules or cells associated with the BMS sub-controllers. Based on this information, the controller 102 may then issue balancing instructions specifically targeted toward a BMS sub-controller or even a module or cell associated with a BMS sub-controller of the battery system. The BMS sub-controller may perform the requested balancing by activating an energy dissipating device for the cell or module in question. In this manner, the controller 102 may control the balancing operation to balance the output of the connected batteries.

Although the present disclosure has been described with respect to particular apparatuses, configurations, components, systems and methods of operation, it will be appreciated by those of ordinary skill in the art upon reading this disclosure that certain changes or modifications to the embodiments and/or their operations, as described herein, may be made without departing from the spirit or scope of the disclosure. Accordingly, the proper scope of the disclosure is defined by the appended claims. The various embodiments, operations, components and configurations disclosed herein are generally exemplary rather than limiting in scope. 

1. A battery management system comprising: a controller comprising: a processing device configured to transmit and receive one or more control signals for configuring a battery system; a downstream communication link; and an upstream communication link; a first sub-controller connected to the downstream communication link and the upstream communication link of the controller, wherein the first sub-controller is configured to receive one or more first power unit control signals from a controller on the downstream communication link and, in response to the one or more first power unit control signals received from the controller, configure a first plurality of battery cells in response; and a second sub-controller connected to the first sub-controller and configured to receive one or more second power unit control signals from the first sub-controller and, in response to the one or more second power unit control signals received from the first sub-controller, configure a second plurality of battery cells.
 2. The battery management system of claim 1 wherein the first sub-controller further comprises: a first sub-controller processing device configured to receive operational information from the first plurality of battery cells; and a first sub-controller computer-readable storage device configured to store operational information of the first plurality of battery cells.
 3. The battery management system of claim 2 wherein, in response to the one or more first power unit control signals received from the controller, the first sub-controller processing device operates to transmit the stored operational information to the controller on the upstream link.
 4. The battery management system of claim 2 wherein the first sub-controller computer-readable storage device is further configured to store the one or more second power unit control signals received from the controller and the first sub-controller processing device operates to transmit the second power unit control signals to the second power unit.
 5. The battery management system of claim 2 wherein the first sub-controller further comprises a power supply configured to receive a power enable signal and provide power to the first sub-controller processing device in response to receiving the power enable signal.
 6. The battery management system of claim 1 wherein a first portion of the first plurality of battery cells are connected into a first battery module and a second portion of the first plurality of battery cells are connected into a second battery module, and wherein further the first battery module and the second battery module are serially connected to the first sub-controller.
 7. The battery management system of claim 6 wherein configuring the first plurality of battery cells in response the first control signal comprises performing a balancing of the voltages of the first battery module and the second battery module.
 8. The battery management system of claim 1 wherein the first plurality of battery cells comprises at least one battery cell of a first chemical composition and at least one battery cell of a second chemical composition.
 9. The battery management system of claim 1 wherein the second power unit is electrically isolated from the first power unit.
 10. The battery management system of claim 1 further comprising: a plurality of additional sub-controllers associated with the second sub-controller and comprising: a plurality sub-controller processing device configured to receive a plurality of power unit control signals from the second power unit and, in response to the plurality of power unit control signals received from the second sub-controller, configure a plurality of battery cells; and a plurality of sub-controller computer-readable storage devices configured to store operational information of the first plurality of battery cells.
 11. A method for control of a battery system comprising a plurality of power units, the method comprising: receiving a first control signal from a controller on a first downstream communication link at a first management control sub-controller associated with a first power unit of the battery system, the first management control sub-controller connected to the controller by the first downstream communication link; configuring at least one setting of the first power unit in response to the received first control signal; receiving at least one performance indicator from the first power unit; storing the at least one performance indicator of the first power unit in a computer-readable storage device associated with the first management control sub-controller; and transmitting a second control signal on a second downstream communication link to a second management control sub-controller associated with a second power unit of the battery, wherein the second control signal is substantially similar to the first control signal.
 12. The method of claim 11 further comprising: receiving a second power unit performance measurement on an upstream communication link configured between the first power unit and the second power unit; and storing the second power unit performance measurement in the computer-readable medium.
 13. The method of claim 12 further comprising: receiving a third control signal from the controller on the first downstream communication link at the first management control sub-controller associated with the first power unit of the battery, the third control signal comprising a request for the second power unit performance measurement; and transmitting the second power unit performance measurement on a first upstream communication link configured between the first power unit and the controller.
 14. The method of claim 11 wherein the first control signal comprises an instruction to the first management control sub-controller associated with the first power unit to perform a balancing of a plurality of battery modules associated with the first power unit.
 15. The method of claim 11 wherein the first control signal comprises a power enable signal to provide power to the first management control sub-controller of the first power unit.
 16. The method of claim 11 wherein the first control signal comprises an initialization command and a first address value and wherein the configuring operation comprises: retrieving the first address value from the first control signal; and storing the first address value in an address register associated with the first power unit.
 17. The method of claim 16 wherein the second control signal comprises the initialization command and a second address value, the second address value an increment of one from the first address value.
 18. A management sub-controller of a power unit of a battery system comprising: a processor; a downstream communication receiver configured to receive one or more control signals from a downstream communication link; an upstream communication transmitter configured to transmit one or more control signals on an upstream communication link, wherein the downstream communication receiver and upstream communication transmitter are electrically isolated from the corresponding downstream link and upstream link; and a computer-readable device with instructions stored thereon that, when executed, cause the processor to perform the operations of: obtaining at least one performance indicator of the power unit of the battery system; storing the at least one performance indicator in the computer-readable device; and transmitting the at least one performance indicator to the upstream communication transmitter for transmission on the upstream communication link.
 19. The management sub-controller of claim 18 wherein the downstream communication receiver is a wired electrically isolated receiver and the transmitter is a wired electrically isolated transmitter.
 20. The management sub-controller of claim 18 wherein the downstream communication receiver is an optical receiver and the transmitter is an optical transmitter. 